1 /* -*- Mode: C; tab-width: 4 -*- 2 * 3 * Copyright (c) 2002-2015 Apple Inc. All rights reserved. 4 * 5 * Licensed under the Apache License, Version 2.0 (the "License"); 6 * you may not use this file except in compliance with the License. 7 * You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 * 17 */ 18 19 #include "mDNSEmbeddedAPI.h" // Defines the interface provided to the client layer above 20 #include "DNSCommon.h" 21 #include "mDNSPosix.h" // Defines the specific types needed to run mDNS on this platform 22 #include "dns_sd.h" 23 #include "dnssec.h" 24 #include "nsec.h" 25 26 #include <assert.h> 27 #include <stdio.h> 28 #include <stdlib.h> 29 #include <errno.h> 30 #include <string.h> 31 #include <unistd.h> 32 #include <syslog.h> 33 #include <stdarg.h> 34 #include <fcntl.h> 35 #include <sys/types.h> 36 #include <sys/time.h> 37 #include <sys/socket.h> 38 #include <sys/uio.h> 39 #include <sys/select.h> 40 #include <netinet/in.h> 41 #include <arpa/inet.h> 42 #include <time.h> // platform support for UTC time 43 44 #if USES_NETLINK 45 #include <asm/types.h> 46 #include <linux/netlink.h> 47 #include <linux/rtnetlink.h> 48 #else // USES_NETLINK 49 #include <net/route.h> 50 #include <net/if.h> 51 #endif // USES_NETLINK 52 53 #include "mDNSUNP.h" 54 #include "GenLinkedList.h" 55 #include "dnsproxy.h" 56 57 // *************************************************************************** 58 // Structures 59 60 // We keep a list of client-supplied event sources in PosixEventSource records 61 struct PosixEventSource 62 { 63 mDNSPosixEventCallback Callback; 64 void *Context; 65 int fd; 66 struct PosixEventSource *Next; 67 }; 68 typedef struct PosixEventSource PosixEventSource; 69 70 // Context record for interface change callback 71 struct IfChangeRec 72 { 73 int NotifySD; 74 mDNS *mDNS; 75 }; 76 typedef struct IfChangeRec IfChangeRec; 77 78 // Note that static data is initialized to zero in (modern) C. 79 static fd_set gEventFDs; 80 static int gMaxFD; // largest fd in gEventFDs 81 static GenLinkedList gEventSources; // linked list of PosixEventSource's 82 static sigset_t gEventSignalSet; // Signals which event loop listens for 83 static sigset_t gEventSignals; // Signals which were received while inside loop 84 85 static PosixNetworkInterface *gRecentInterfaces; 86 87 // *************************************************************************** 88 // Globals (for debugging) 89 90 static int num_registered_interfaces = 0; 91 static int num_pkts_accepted = 0; 92 static int num_pkts_rejected = 0; 93 94 // *************************************************************************** 95 // Functions 96 97 int gMDNSPlatformPosixVerboseLevel = 0; 98 99 #define PosixErrorToStatus(errNum) ((errNum) == 0 ? mStatus_NoError : mStatus_UnknownErr) 100 101 mDNSlocal void SockAddrTomDNSAddr(const struct sockaddr *const sa, mDNSAddr *ipAddr, mDNSIPPort *ipPort) 102 { 103 switch (sa->sa_family) 104 { 105 case AF_INET: 106 { 107 struct sockaddr_in *sin = (struct sockaddr_in*)sa; 108 ipAddr->type = mDNSAddrType_IPv4; 109 ipAddr->ip.v4.NotAnInteger = sin->sin_addr.s_addr; 110 if (ipPort) ipPort->NotAnInteger = sin->sin_port; 111 break; 112 } 113 114 #if HAVE_IPV6 115 case AF_INET6: 116 { 117 struct sockaddr_in6 *sin6 = (struct sockaddr_in6*)sa; 118 #ifndef NOT_HAVE_SA_LEN 119 assert(sin6->sin6_len == sizeof(*sin6)); 120 #endif 121 ipAddr->type = mDNSAddrType_IPv6; 122 ipAddr->ip.v6 = *(mDNSv6Addr*)&sin6->sin6_addr; 123 if (ipPort) ipPort->NotAnInteger = sin6->sin6_port; 124 break; 125 } 126 #endif 127 128 default: 129 verbosedebugf("SockAddrTomDNSAddr: Uknown address family %d\n", sa->sa_family); 130 ipAddr->type = mDNSAddrType_None; 131 if (ipPort) ipPort->NotAnInteger = 0; 132 break; 133 } 134 } 135 136 #if COMPILER_LIKES_PRAGMA_MARK 137 #pragma mark ***** Send and Receive 138 #endif 139 140 // mDNS core calls this routine when it needs to send a packet. 141 mDNSexport mStatus mDNSPlatformSendUDP(const mDNS *const m, const void *const msg, const mDNSu8 *const end, 142 mDNSInterfaceID InterfaceID, UDPSocket *src, const mDNSAddr *dst, 143 mDNSIPPort dstPort, mDNSBool useBackgroundTrafficClass) 144 { 145 int err = 0; 146 struct sockaddr_storage to; 147 PosixNetworkInterface * thisIntf = (PosixNetworkInterface *)(InterfaceID); 148 int sendingsocket = -1; 149 150 (void)src; // Will need to use this parameter once we implement mDNSPlatformUDPSocket/mDNSPlatformUDPClose 151 (void) useBackgroundTrafficClass; 152 153 assert(m != NULL); 154 assert(msg != NULL); 155 assert(end != NULL); 156 assert((((char *) end) - ((char *) msg)) > 0); 157 158 if (dstPort.NotAnInteger == 0) 159 { 160 LogMsg("mDNSPlatformSendUDP: Invalid argument -dstPort is set to 0"); 161 return PosixErrorToStatus(EINVAL); 162 } 163 if (dst->type == mDNSAddrType_IPv4) 164 { 165 struct sockaddr_in *sin = (struct sockaddr_in*)&to; 166 #ifndef NOT_HAVE_SA_LEN 167 sin->sin_len = sizeof(*sin); 168 #endif 169 sin->sin_family = AF_INET; 170 sin->sin_port = dstPort.NotAnInteger; 171 sin->sin_addr.s_addr = dst->ip.v4.NotAnInteger; 172 sendingsocket = thisIntf ? thisIntf->multicastSocket4 : m->p->unicastSocket4; 173 } 174 175 #if HAVE_IPV6 176 else if (dst->type == mDNSAddrType_IPv6) 177 { 178 struct sockaddr_in6 *sin6 = (struct sockaddr_in6*)&to; 179 mDNSPlatformMemZero(sin6, sizeof(*sin6)); 180 #ifndef NOT_HAVE_SA_LEN 181 sin6->sin6_len = sizeof(*sin6); 182 #endif 183 sin6->sin6_family = AF_INET6; 184 sin6->sin6_port = dstPort.NotAnInteger; 185 sin6->sin6_addr = *(struct in6_addr*)&dst->ip.v6; 186 sendingsocket = thisIntf ? thisIntf->multicastSocket6 : m->p->unicastSocket6; 187 } 188 #endif 189 190 if (sendingsocket >= 0) 191 err = sendto(sendingsocket, msg, (char*)end - (char*)msg, 0, (struct sockaddr *)&to, GET_SA_LEN(to)); 192 193 if (err > 0) err = 0; 194 else if (err < 0) 195 { 196 static int MessageCount = 0; 197 // Don't report EHOSTDOWN (i.e. ARP failure), ENETDOWN, or no route to host for unicast destinations 198 if (!mDNSAddressIsAllDNSLinkGroup(dst)) 199 if (errno == EHOSTDOWN || errno == ENETDOWN || errno == EHOSTUNREACH || errno == ENETUNREACH) return(mStatus_TransientErr); 200 201 /* dont report ENETUNREACH */ 202 if (errno == ENETUNREACH) return(mStatus_TransientErr); 203 204 if (MessageCount < 1000) 205 { 206 MessageCount++; 207 if (thisIntf) 208 LogMsg("mDNSPlatformSendUDP got error %d (%s) sending packet to %#a on interface %#a/%s/%d", 209 errno, strerror(errno), dst, &thisIntf->coreIntf.ip, thisIntf->intfName, thisIntf->index); 210 else 211 LogMsg("mDNSPlatformSendUDP got error %d (%s) sending packet to %#a", errno, strerror(errno), dst); 212 } 213 } 214 215 return PosixErrorToStatus(err); 216 } 217 218 // This routine is called when the main loop detects that data is available on a socket. 219 mDNSlocal void SocketDataReady(mDNS *const m, PosixNetworkInterface *intf, int skt) 220 { 221 mDNSAddr senderAddr, destAddr; 222 mDNSIPPort senderPort; 223 ssize_t packetLen; 224 DNSMessage packet; 225 struct my_in_pktinfo packetInfo; 226 struct sockaddr_storage from; 227 socklen_t fromLen; 228 int flags; 229 mDNSu8 ttl; 230 mDNSBool reject; 231 const mDNSInterfaceID InterfaceID = intf ? intf->coreIntf.InterfaceID : NULL; 232 233 assert(m != NULL); 234 assert(skt >= 0); 235 236 fromLen = sizeof(from); 237 flags = 0; 238 packetLen = recvfrom_flags(skt, &packet, sizeof(packet), &flags, (struct sockaddr *) &from, &fromLen, &packetInfo, &ttl); 239 240 if (packetLen >= 0) 241 { 242 SockAddrTomDNSAddr((struct sockaddr*)&from, &senderAddr, &senderPort); 243 SockAddrTomDNSAddr((struct sockaddr*)&packetInfo.ipi_addr, &destAddr, NULL); 244 245 // If we have broken IP_RECVDSTADDR functionality (so far 246 // I've only seen this on OpenBSD) then apply a hack to 247 // convince mDNS Core that this isn't a spoof packet. 248 // Basically what we do is check to see whether the 249 // packet arrived as a multicast and, if so, set its 250 // destAddr to the mDNS address. 251 // 252 // I must admit that I could just be doing something 253 // wrong on OpenBSD and hence triggering this problem 254 // but I'm at a loss as to how. 255 // 256 // If this platform doesn't have IP_PKTINFO or IP_RECVDSTADDR, then we have 257 // no way to tell the destination address or interface this packet arrived on, 258 // so all we can do is just assume it's a multicast 259 260 #if HAVE_BROKEN_RECVDSTADDR || (!defined(IP_PKTINFO) && !defined(IP_RECVDSTADDR)) 261 if ((destAddr.NotAnInteger == 0) && (flags & MSG_MCAST)) 262 { 263 destAddr.type = senderAddr.type; 264 if (senderAddr.type == mDNSAddrType_IPv4) destAddr.ip.v4 = AllDNSLinkGroup_v4.ip.v4; 265 else if (senderAddr.type == mDNSAddrType_IPv6) destAddr.ip.v6 = AllDNSLinkGroup_v6.ip.v6; 266 } 267 #endif 268 269 // We only accept the packet if the interface on which it came 270 // in matches the interface associated with this socket. 271 // We do this match by name or by index, depending on which 272 // information is available. recvfrom_flags sets the name 273 // to "" if the name isn't available, or the index to -1 274 // if the index is available. This accomodates the various 275 // different capabilities of our target platforms. 276 277 reject = mDNSfalse; 278 if (!intf) 279 { 280 // Ignore multicasts accidentally delivered to our unicast receiving socket 281 if (mDNSAddrIsDNSMulticast(&destAddr)) packetLen = -1; 282 } 283 else 284 { 285 if (packetInfo.ipi_ifname[0] != 0) reject = (strcmp(packetInfo.ipi_ifname, intf->intfName) != 0); 286 else if (packetInfo.ipi_ifindex != -1) reject = (packetInfo.ipi_ifindex != intf->index); 287 288 if (reject) 289 { 290 verbosedebugf("SocketDataReady ignored a packet from %#a to %#a on interface %s/%d expecting %#a/%s/%d/%d", 291 &senderAddr, &destAddr, packetInfo.ipi_ifname, packetInfo.ipi_ifindex, 292 &intf->coreIntf.ip, intf->intfName, intf->index, skt); 293 packetLen = -1; 294 num_pkts_rejected++; 295 if (num_pkts_rejected > (num_pkts_accepted + 1) * (num_registered_interfaces + 1) * 2) 296 { 297 fprintf(stderr, 298 "*** WARNING: Received %d packets; Accepted %d packets; Rejected %d packets because of interface mismatch\n", 299 num_pkts_accepted + num_pkts_rejected, num_pkts_accepted, num_pkts_rejected); 300 num_pkts_accepted = 0; 301 num_pkts_rejected = 0; 302 } 303 } 304 else 305 { 306 verbosedebugf("SocketDataReady got a packet from %#a to %#a on interface %#a/%s/%d/%d", 307 &senderAddr, &destAddr, &intf->coreIntf.ip, intf->intfName, intf->index, skt); 308 num_pkts_accepted++; 309 } 310 } 311 } 312 313 if (packetLen >= 0) 314 mDNSCoreReceive(m, &packet, (mDNSu8 *)&packet + packetLen, 315 &senderAddr, senderPort, &destAddr, MulticastDNSPort, InterfaceID); 316 } 317 318 mDNSexport TCPSocket *mDNSPlatformTCPSocket(TCPSocketFlags flags, mDNSIPPort * port, mDNSBool useBackgroundTrafficClass) 319 { 320 (void)flags; // Unused 321 (void)port; // Unused 322 (void)useBackgroundTrafficClass; // Unused 323 return NULL; 324 } 325 326 mDNSexport TCPSocket *mDNSPlatformTCPAccept(TCPSocketFlags flags, int sd) 327 { 328 (void)flags; // Unused 329 (void)sd; // Unused 330 return NULL; 331 } 332 333 mDNSexport int mDNSPlatformTCPGetFD(TCPSocket *sock) 334 { 335 (void)sock; // Unused 336 return -1; 337 } 338 339 mDNSexport mStatus mDNSPlatformTCPConnect(TCPSocket *sock, const mDNSAddr *dst, mDNSOpaque16 dstport, domainname *hostname, mDNSInterfaceID InterfaceID, 340 TCPConnectionCallback callback, void *context) 341 { 342 (void)sock; // Unused 343 (void)dst; // Unused 344 (void)dstport; // Unused 345 (void)hostname; // Unused 346 (void)InterfaceID; // Unused 347 (void)callback; // Unused 348 (void)context; // Unused 349 return(mStatus_UnsupportedErr); 350 } 351 352 mDNSexport void mDNSPlatformTCPCloseConnection(TCPSocket *sock) 353 { 354 (void)sock; // Unused 355 } 356 357 mDNSexport long mDNSPlatformReadTCP(TCPSocket *sock, void *buf, unsigned long buflen, mDNSBool * closed) 358 { 359 (void)sock; // Unused 360 (void)buf; // Unused 361 (void)buflen; // Unused 362 (void)closed; // Unused 363 return 0; 364 } 365 366 mDNSexport long mDNSPlatformWriteTCP(TCPSocket *sock, const char *msg, unsigned long len) 367 { 368 (void)sock; // Unused 369 (void)msg; // Unused 370 (void)len; // Unused 371 return 0; 372 } 373 374 mDNSexport UDPSocket *mDNSPlatformUDPSocket(mDNSIPPort port) 375 { 376 (void)port; // Unused 377 return NULL; 378 } 379 380 mDNSexport void mDNSPlatformUDPClose(UDPSocket *sock) 381 { 382 (void)sock; // Unused 383 } 384 385 mDNSexport void mDNSPlatformUpdateProxyList(const mDNSInterfaceID InterfaceID) 386 { 387 (void)InterfaceID; // Unused 388 } 389 390 mDNSexport void mDNSPlatformSendRawPacket(const void *const msg, const mDNSu8 *const end, mDNSInterfaceID InterfaceID) 391 { 392 (void)msg; // Unused 393 (void)end; // Unused 394 (void)InterfaceID; // Unused 395 } 396 397 mDNSexport void mDNSPlatformSetLocalAddressCacheEntry(const mDNSAddr *const tpa, const mDNSEthAddr *const tha, mDNSInterfaceID InterfaceID) 398 { 399 (void)tpa; // Unused 400 (void)tha; // Unused 401 (void)InterfaceID; // Unused 402 } 403 404 mDNSexport mStatus mDNSPlatformTLSSetupCerts(void) 405 { 406 return(mStatus_UnsupportedErr); 407 } 408 409 mDNSexport void mDNSPlatformTLSTearDownCerts(void) 410 { 411 } 412 413 mDNSexport void mDNSPlatformSetAllowSleep(mDNSBool allowSleep, const char *reason) 414 { 415 (void) allowSleep; 416 (void) reason; 417 } 418 419 #if COMPILER_LIKES_PRAGMA_MARK 420 #pragma mark - 421 #pragma mark - /etc/hosts support 422 #endif 423 424 mDNSexport void FreeEtcHosts(mDNS *const m, AuthRecord *const rr, mStatus result) 425 { 426 (void)m; // unused 427 (void)rr; 428 (void)result; 429 } 430 431 432 #if COMPILER_LIKES_PRAGMA_MARK 433 #pragma mark ***** DDNS Config Platform Functions 434 #endif 435 436 mDNSexport mDNSBool mDNSPlatformSetDNSConfig(mDNSBool setservers, mDNSBool setsearch, domainname *const fqdn, DNameListElem **RegDomains, 437 DNameListElem **BrowseDomains, mDNSBool ackConfig) 438 { 439 (void) setservers; 440 if (fqdn) fqdn->c[0] = 0; 441 (void) setsearch; 442 if (RegDomains) *RegDomains = NULL; 443 if (BrowseDomains) *BrowseDomains = NULL; 444 (void) ackConfig; 445 446 return mDNStrue; 447 } 448 449 mDNSexport mStatus mDNSPlatformGetPrimaryInterface(mDNSAddr * v4, mDNSAddr * v6, mDNSAddr * router) 450 { 451 (void) v4; 452 (void) v6; 453 (void) router; 454 455 return mStatus_UnsupportedErr; 456 } 457 458 mDNSexport void mDNSPlatformDynDNSHostNameStatusChanged(const domainname *const dname, const mStatus status) 459 { 460 (void) dname; 461 (void) status; 462 } 463 464 #if COMPILER_LIKES_PRAGMA_MARK 465 #pragma mark ***** Init and Term 466 #endif 467 468 // This gets the current hostname, truncating it at the first dot if necessary 469 mDNSlocal void GetUserSpecifiedRFC1034ComputerName(domainlabel *const namelabel) 470 { 471 int len = 0; 472 gethostname((char *)(&namelabel->c[1]), MAX_DOMAIN_LABEL); 473 while (len < MAX_DOMAIN_LABEL && namelabel->c[len+1] && namelabel->c[len+1] != '.') len++; 474 namelabel->c[0] = len; 475 } 476 477 // On OS X this gets the text of the field labelled "Computer Name" in the Sharing Prefs Control Panel 478 // Other platforms can either get the information from the appropriate place, 479 // or they can alternatively just require all registering services to provide an explicit name 480 mDNSlocal void GetUserSpecifiedFriendlyComputerName(domainlabel *const namelabel) 481 { 482 // On Unix we have no better name than the host name, so we just use that. 483 GetUserSpecifiedRFC1034ComputerName(namelabel); 484 } 485 486 mDNSexport int ParseDNSServers(mDNS *m, const char *filePath) 487 { 488 char line[256]; 489 char nameserver[16]; 490 char keyword[11]; 491 int numOfServers = 0; 492 FILE *fp = fopen(filePath, "r"); 493 if (fp == NULL) return -1; 494 while (fgets(line,sizeof(line),fp)) 495 { 496 struct in_addr ina; 497 line[255]='\0'; // just to be safe 498 if (sscanf(line,"%10s %15s", keyword, nameserver) != 2) continue; // it will skip whitespaces 499 if (strncasecmp(keyword,"nameserver",10)) continue; 500 if (inet_aton(nameserver, (struct in_addr *)&ina) != 0) 501 { 502 mDNSAddr DNSAddr; 503 DNSAddr.type = mDNSAddrType_IPv4; 504 DNSAddr.ip.v4.NotAnInteger = ina.s_addr; 505 mDNS_AddDNSServer(m, NULL, mDNSInterface_Any, 0, &DNSAddr, UnicastDNSPort, kScopeNone, 0, mDNSfalse, mDNSfalse, mDNSfalse, 0, mDNStrue, mDNStrue, mDNSfalse); 506 numOfServers++; 507 } 508 } 509 fclose(fp); 510 return (numOfServers > 0) ? 0 : -1; 511 } 512 513 // Searches the interface list looking for the named interface. 514 // Returns a pointer to if it found, or NULL otherwise. 515 mDNSlocal PosixNetworkInterface *SearchForInterfaceByName(mDNS *const m, const char *intfName) 516 { 517 PosixNetworkInterface *intf; 518 519 assert(m != NULL); 520 assert(intfName != NULL); 521 522 intf = (PosixNetworkInterface*)(m->HostInterfaces); 523 while ((intf != NULL) && (strcmp(intf->intfName, intfName) != 0)) 524 intf = (PosixNetworkInterface *)(intf->coreIntf.next); 525 526 return intf; 527 } 528 529 mDNSexport mDNSInterfaceID mDNSPlatformInterfaceIDfromInterfaceIndex(mDNS *const m, mDNSu32 index) 530 { 531 PosixNetworkInterface *intf; 532 533 assert(m != NULL); 534 535 if (index == kDNSServiceInterfaceIndexLocalOnly) return(mDNSInterface_LocalOnly); 536 if (index == kDNSServiceInterfaceIndexP2P ) return(mDNSInterface_P2P); 537 if (index == kDNSServiceInterfaceIndexAny ) return(mDNSInterface_Any); 538 539 intf = (PosixNetworkInterface*)(m->HostInterfaces); 540 while ((intf != NULL) && (mDNSu32) intf->index != index) 541 intf = (PosixNetworkInterface *)(intf->coreIntf.next); 542 543 return (mDNSInterfaceID) intf; 544 } 545 546 mDNSexport mDNSu32 mDNSPlatformInterfaceIndexfromInterfaceID(mDNS *const m, mDNSInterfaceID id, mDNSBool suppressNetworkChange) 547 { 548 PosixNetworkInterface *intf; 549 (void) suppressNetworkChange; // Unused 550 551 assert(m != NULL); 552 553 if (id == mDNSInterface_LocalOnly) return(kDNSServiceInterfaceIndexLocalOnly); 554 if (id == mDNSInterface_P2P ) return(kDNSServiceInterfaceIndexP2P); 555 if (id == mDNSInterface_Any ) return(kDNSServiceInterfaceIndexAny); 556 557 intf = (PosixNetworkInterface*)(m->HostInterfaces); 558 while ((intf != NULL) && (mDNSInterfaceID) intf != id) 559 intf = (PosixNetworkInterface *)(intf->coreIntf.next); 560 561 if (intf) return intf->index; 562 563 // If we didn't find the interface, check the RecentInterfaces list as well 564 intf = gRecentInterfaces; 565 while ((intf != NULL) && (mDNSInterfaceID) intf != id) 566 intf = (PosixNetworkInterface *)(intf->coreIntf.next); 567 568 return intf ? intf->index : 0; 569 } 570 571 // Frees the specified PosixNetworkInterface structure. The underlying 572 // interface must have already been deregistered with the mDNS core. 573 mDNSlocal void FreePosixNetworkInterface(PosixNetworkInterface *intf) 574 { 575 int rv; 576 assert(intf != NULL); 577 if (intf->intfName != NULL) free((void *)intf->intfName); 578 if (intf->multicastSocket4 != -1) 579 { 580 rv = close(intf->multicastSocket4); 581 assert(rv == 0); 582 } 583 #if HAVE_IPV6 584 if (intf->multicastSocket6 != -1) 585 { 586 rv = close(intf->multicastSocket6); 587 assert(rv == 0); 588 } 589 #endif 590 591 // Move interface to the RecentInterfaces list for a minute 592 intf->LastSeen = mDNSPlatformUTC(); 593 intf->coreIntf.next = &gRecentInterfaces->coreIntf; 594 gRecentInterfaces = intf; 595 } 596 597 // Grab the first interface, deregister it, free it, and repeat until done. 598 mDNSlocal void ClearInterfaceList(mDNS *const m) 599 { 600 assert(m != NULL); 601 602 while (m->HostInterfaces) 603 { 604 PosixNetworkInterface *intf = (PosixNetworkInterface*)(m->HostInterfaces); 605 mDNS_DeregisterInterface(m, &intf->coreIntf, NormalActivation); 606 if (gMDNSPlatformPosixVerboseLevel > 0) fprintf(stderr, "Deregistered interface %s\n", intf->intfName); 607 FreePosixNetworkInterface(intf); 608 } 609 num_registered_interfaces = 0; 610 num_pkts_accepted = 0; 611 num_pkts_rejected = 0; 612 } 613 614 // Sets up a send/receive socket. 615 // If mDNSIPPort port is non-zero, then it's a multicast socket on the specified interface 616 // If mDNSIPPort port is zero, then it's a randomly assigned port number, used for sending unicast queries 617 mDNSlocal int SetupSocket(struct sockaddr *intfAddr, mDNSIPPort port, int interfaceIndex, int *sktPtr) 618 { 619 int err = 0; 620 static const int kOn = 1; 621 static const int kIntTwoFiveFive = 255; 622 static const unsigned char kByteTwoFiveFive = 255; 623 const mDNSBool JoinMulticastGroup = (port.NotAnInteger != 0); 624 625 (void) interfaceIndex; // This parameter unused on plaforms that don't have IPv6 626 assert(intfAddr != NULL); 627 assert(sktPtr != NULL); 628 assert(*sktPtr == -1); 629 630 // Open the socket... 631 if (intfAddr->sa_family == AF_INET) *sktPtr = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP); 632 #if HAVE_IPV6 633 else if (intfAddr->sa_family == AF_INET6) *sktPtr = socket(PF_INET6, SOCK_DGRAM, IPPROTO_UDP); 634 #endif 635 else return EINVAL; 636 637 if (*sktPtr < 0) { err = errno; perror((intfAddr->sa_family == AF_INET) ? "socket AF_INET" : "socket AF_INET6"); } 638 639 // ... with a shared UDP port, if it's for multicast receiving 640 if (err == 0 && port.NotAnInteger) 641 { 642 // <rdar://problem/20946253> 643 // We test for SO_REUSEADDR first, as suggested by Jonny Törnbom from Axis Communications 644 // Linux kernel versions 3.9 introduces support for socket option 645 // SO_REUSEPORT, however this is not implemented the same as on *BSD 646 // systems. Linux version implements a "port hijacking" prevention 647 // mechanism, limiting processes wanting to bind to an already existing 648 // addr:port to have the same effective UID as the first who bound it. What 649 // this meant for us was that the daemon ran as one user and when for 650 // instance mDNSClientPosix was executed by another user, it wasn't allowed 651 // to bind to the socket. Our suggestion was to switch the order in which 652 // SO_REUSEPORT and SO_REUSEADDR was tested so that SO_REUSEADDR stays on 653 // top and SO_REUSEPORT to be used only if SO_REUSEADDR doesn't exist. 654 #if defined(SO_REUSEADDR) && !defined(__MAC_OS_X_VERSION_MIN_REQUIRED) 655 err = setsockopt(*sktPtr, SOL_SOCKET, SO_REUSEADDR, &kOn, sizeof(kOn)); 656 #elif defined(SO_REUSEPORT) 657 err = setsockopt(*sktPtr, SOL_SOCKET, SO_REUSEPORT, &kOn, sizeof(kOn)); 658 #else 659 #error This platform has no way to avoid address busy errors on multicast. 660 #endif 661 if (err < 0) { err = errno; perror("setsockopt - SO_REUSExxxx"); } 662 663 // Enable inbound packets on IFEF_AWDL interface. 664 // Only done for multicast sockets, since we don't expect unicast socket operations 665 // on the IFEF_AWDL interface. Operation is a no-op for other interface types. 666 #ifdef SO_RECV_ANYIF 667 if (setsockopt(*sktPtr, SOL_SOCKET, SO_RECV_ANYIF, &kOn, sizeof(kOn)) < 0) perror("setsockopt - SO_RECV_ANYIF"); 668 #endif 669 } 670 671 // We want to receive destination addresses and interface identifiers. 672 if (intfAddr->sa_family == AF_INET) 673 { 674 struct ip_mreq imr; 675 struct sockaddr_in bindAddr; 676 if (err == 0) 677 { 678 #if defined(IP_PKTINFO) // Linux 679 err = setsockopt(*sktPtr, IPPROTO_IP, IP_PKTINFO, &kOn, sizeof(kOn)); 680 if (err < 0) { err = errno; perror("setsockopt - IP_PKTINFO"); } 681 #elif defined(IP_RECVDSTADDR) || defined(IP_RECVIF) // BSD and Solaris 682 #if defined(IP_RECVDSTADDR) 683 err = setsockopt(*sktPtr, IPPROTO_IP, IP_RECVDSTADDR, &kOn, sizeof(kOn)); 684 if (err < 0) { err = errno; perror("setsockopt - IP_RECVDSTADDR"); } 685 #endif 686 #if defined(IP_RECVIF) 687 if (err == 0) 688 { 689 err = setsockopt(*sktPtr, IPPROTO_IP, IP_RECVIF, &kOn, sizeof(kOn)); 690 if (err < 0) { err = errno; perror("setsockopt - IP_RECVIF"); } 691 } 692 #endif 693 #else 694 #warning This platform has no way to get the destination interface information -- will only work for single-homed hosts 695 #endif 696 } 697 #if defined(IP_RECVTTL) // Linux 698 if (err == 0) 699 { 700 setsockopt(*sktPtr, IPPROTO_IP, IP_RECVTTL, &kOn, sizeof(kOn)); 701 // We no longer depend on being able to get the received TTL, so don't worry if the option fails 702 } 703 #endif 704 705 // Add multicast group membership on this interface 706 if (err == 0 && JoinMulticastGroup) 707 { 708 imr.imr_multiaddr.s_addr = AllDNSLinkGroup_v4.ip.v4.NotAnInteger; 709 imr.imr_interface = ((struct sockaddr_in*)intfAddr)->sin_addr; 710 err = setsockopt(*sktPtr, IPPROTO_IP, IP_ADD_MEMBERSHIP, &imr, sizeof(imr)); 711 if (err < 0) { err = errno; perror("setsockopt - IP_ADD_MEMBERSHIP"); } 712 } 713 714 // Specify outgoing interface too 715 if (err == 0 && JoinMulticastGroup) 716 { 717 err = setsockopt(*sktPtr, IPPROTO_IP, IP_MULTICAST_IF, &((struct sockaddr_in*)intfAddr)->sin_addr, sizeof(struct in_addr)); 718 if (err < 0) { err = errno; perror("setsockopt - IP_MULTICAST_IF"); } 719 } 720 721 // Per the mDNS spec, send unicast packets with TTL 255 722 if (err == 0) 723 { 724 err = setsockopt(*sktPtr, IPPROTO_IP, IP_TTL, &kIntTwoFiveFive, sizeof(kIntTwoFiveFive)); 725 if (err < 0) { err = errno; perror("setsockopt - IP_TTL"); } 726 } 727 728 // and multicast packets with TTL 255 too 729 // There's some debate as to whether IP_MULTICAST_TTL is an int or a byte so we just try both. 730 if (err == 0) 731 { 732 err = setsockopt(*sktPtr, IPPROTO_IP, IP_MULTICAST_TTL, &kByteTwoFiveFive, sizeof(kByteTwoFiveFive)); 733 if (err < 0 && errno == EINVAL) 734 err = setsockopt(*sktPtr, IPPROTO_IP, IP_MULTICAST_TTL, &kIntTwoFiveFive, sizeof(kIntTwoFiveFive)); 735 if (err < 0) { err = errno; perror("setsockopt - IP_MULTICAST_TTL"); } 736 } 737 738 // And start listening for packets 739 if (err == 0) 740 { 741 bindAddr.sin_family = AF_INET; 742 bindAddr.sin_port = port.NotAnInteger; 743 bindAddr.sin_addr.s_addr = INADDR_ANY; // Want to receive multicasts AND unicasts on this socket 744 err = bind(*sktPtr, (struct sockaddr *) &bindAddr, sizeof(bindAddr)); 745 if (err < 0) { err = errno; perror("bind"); fflush(stderr); } 746 } 747 } // endif (intfAddr->sa_family == AF_INET) 748 749 #if HAVE_IPV6 750 else if (intfAddr->sa_family == AF_INET6) 751 { 752 struct ipv6_mreq imr6; 753 struct sockaddr_in6 bindAddr6; 754 #if defined(IPV6_RECVPKTINFO) // Solaris 755 if (err == 0) 756 { 757 err = setsockopt(*sktPtr, IPPROTO_IPV6, IPV6_RECVPKTINFO, &kOn, sizeof(kOn)); 758 if (err < 0) { err = errno; perror("setsockopt - IPV6_RECVPKTINFO"); } 759 } 760 #elif defined(IPV6_PKTINFO) 761 if (err == 0) 762 { 763 err = setsockopt(*sktPtr, IPPROTO_IPV6, IPV6_2292_PKTINFO, &kOn, sizeof(kOn)); 764 if (err < 0) { err = errno; perror("setsockopt - IPV6_PKTINFO"); } 765 } 766 #else 767 #warning This platform has no way to get the destination interface information for IPv6 -- will only work for single-homed hosts 768 #endif 769 #if defined(IPV6_RECVHOPLIMIT) 770 if (err == 0) 771 { 772 err = setsockopt(*sktPtr, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &kOn, sizeof(kOn)); 773 if (err < 0) { err = errno; perror("setsockopt - IPV6_RECVHOPLIMIT"); } 774 } 775 #elif defined(IPV6_HOPLIMIT) 776 if (err == 0) 777 { 778 err = setsockopt(*sktPtr, IPPROTO_IPV6, IPV6_2292_HOPLIMIT, &kOn, sizeof(kOn)); 779 if (err < 0) { err = errno; perror("setsockopt - IPV6_HOPLIMIT"); } 780 } 781 #endif 782 783 // Add multicast group membership on this interface 784 if (err == 0 && JoinMulticastGroup) 785 { 786 imr6.ipv6mr_multiaddr = *(const struct in6_addr*)&AllDNSLinkGroup_v6.ip.v6; 787 imr6.ipv6mr_interface = interfaceIndex; 788 //LogMsg("Joining %.16a on %d", &imr6.ipv6mr_multiaddr, imr6.ipv6mr_interface); 789 err = setsockopt(*sktPtr, IPPROTO_IPV6, IPV6_JOIN_GROUP, &imr6, sizeof(imr6)); 790 if (err < 0) 791 { 792 err = errno; 793 verbosedebugf("IPV6_JOIN_GROUP %.16a on %d failed.\n", &imr6.ipv6mr_multiaddr, imr6.ipv6mr_interface); 794 perror("setsockopt - IPV6_JOIN_GROUP"); 795 } 796 } 797 798 // Specify outgoing interface too 799 if (err == 0 && JoinMulticastGroup) 800 { 801 u_int multicast_if = interfaceIndex; 802 err = setsockopt(*sktPtr, IPPROTO_IPV6, IPV6_MULTICAST_IF, &multicast_if, sizeof(multicast_if)); 803 if (err < 0) { err = errno; perror("setsockopt - IPV6_MULTICAST_IF"); } 804 } 805 806 // We want to receive only IPv6 packets on this socket. 807 // Without this option, we may get IPv4 addresses as mapped addresses. 808 if (err == 0) 809 { 810 err = setsockopt(*sktPtr, IPPROTO_IPV6, IPV6_V6ONLY, &kOn, sizeof(kOn)); 811 if (err < 0) { err = errno; perror("setsockopt - IPV6_V6ONLY"); } 812 } 813 814 // Per the mDNS spec, send unicast packets with TTL 255 815 if (err == 0) 816 { 817 err = setsockopt(*sktPtr, IPPROTO_IPV6, IPV6_UNICAST_HOPS, &kIntTwoFiveFive, sizeof(kIntTwoFiveFive)); 818 if (err < 0) { err = errno; perror("setsockopt - IPV6_UNICAST_HOPS"); } 819 } 820 821 // and multicast packets with TTL 255 too 822 // There's some debate as to whether IPV6_MULTICAST_HOPS is an int or a byte so we just try both. 823 if (err == 0) 824 { 825 err = setsockopt(*sktPtr, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &kByteTwoFiveFive, sizeof(kByteTwoFiveFive)); 826 if (err < 0 && errno == EINVAL) 827 err = setsockopt(*sktPtr, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &kIntTwoFiveFive, sizeof(kIntTwoFiveFive)); 828 if (err < 0) { err = errno; perror("setsockopt - IPV6_MULTICAST_HOPS"); } 829 } 830 831 // And start listening for packets 832 if (err == 0) 833 { 834 mDNSPlatformMemZero(&bindAddr6, sizeof(bindAddr6)); 835 #ifndef NOT_HAVE_SA_LEN 836 bindAddr6.sin6_len = sizeof(bindAddr6); 837 #endif 838 bindAddr6.sin6_family = AF_INET6; 839 bindAddr6.sin6_port = port.NotAnInteger; 840 bindAddr6.sin6_flowinfo = 0; 841 bindAddr6.sin6_addr = in6addr_any; // Want to receive multicasts AND unicasts on this socket 842 bindAddr6.sin6_scope_id = 0; 843 err = bind(*sktPtr, (struct sockaddr *) &bindAddr6, sizeof(bindAddr6)); 844 if (err < 0) { err = errno; perror("bind"); fflush(stderr); } 845 } 846 } // endif (intfAddr->sa_family == AF_INET6) 847 #endif 848 849 // Set the socket to non-blocking. 850 if (err == 0) 851 { 852 err = fcntl(*sktPtr, F_GETFL, 0); 853 if (err < 0) err = errno; 854 else 855 { 856 err = fcntl(*sktPtr, F_SETFL, err | O_NONBLOCK); 857 if (err < 0) err = errno; 858 } 859 } 860 861 // Clean up 862 if (err != 0 && *sktPtr != -1) 863 { 864 int rv; 865 rv = close(*sktPtr); 866 assert(rv == 0); 867 *sktPtr = -1; 868 } 869 assert((err == 0) == (*sktPtr != -1)); 870 return err; 871 } 872 873 // Creates a PosixNetworkInterface for the interface whose IP address is 874 // intfAddr and whose name is intfName and registers it with mDNS core. 875 mDNSlocal int SetupOneInterface(mDNS *const m, struct sockaddr *intfAddr, struct sockaddr *intfMask, const char *intfName, int intfIndex) 876 { 877 int err = 0; 878 PosixNetworkInterface *intf; 879 PosixNetworkInterface *alias = NULL; 880 881 assert(m != NULL); 882 assert(intfAddr != NULL); 883 assert(intfName != NULL); 884 assert(intfMask != NULL); 885 886 // Allocate the interface structure itself. 887 intf = (PosixNetworkInterface*)calloc(1, sizeof(*intf)); 888 if (intf == NULL) { assert(0); err = ENOMEM; } 889 890 // And make a copy of the intfName. 891 if (err == 0) 892 { 893 intf->intfName = strdup(intfName); 894 if (intf->intfName == NULL) { assert(0); err = ENOMEM; } 895 } 896 897 if (err == 0) 898 { 899 // Set up the fields required by the mDNS core. 900 SockAddrTomDNSAddr(intfAddr, &intf->coreIntf.ip, NULL); 901 SockAddrTomDNSAddr(intfMask, &intf->coreIntf.mask, NULL); 902 903 //LogMsg("SetupOneInterface: %#a %#a", &intf->coreIntf.ip, &intf->coreIntf.mask); 904 strncpy(intf->coreIntf.ifname, intfName, sizeof(intf->coreIntf.ifname)); 905 intf->coreIntf.ifname[sizeof(intf->coreIntf.ifname)-1] = 0; 906 intf->coreIntf.Advertise = m->AdvertiseLocalAddresses; 907 intf->coreIntf.McastTxRx = mDNStrue; 908 909 // Set up the extra fields in PosixNetworkInterface. 910 assert(intf->intfName != NULL); // intf->intfName already set up above 911 intf->index = intfIndex; 912 intf->multicastSocket4 = -1; 913 #if HAVE_IPV6 914 intf->multicastSocket6 = -1; 915 #endif 916 alias = SearchForInterfaceByName(m, intf->intfName); 917 if (alias == NULL) alias = intf; 918 intf->coreIntf.InterfaceID = (mDNSInterfaceID)alias; 919 920 if (alias != intf) 921 debugf("SetupOneInterface: %s %#a is an alias of %#a", intfName, &intf->coreIntf.ip, &alias->coreIntf.ip); 922 } 923 924 // Set up the multicast socket 925 if (err == 0) 926 { 927 if (alias->multicastSocket4 == -1 && intfAddr->sa_family == AF_INET) 928 err = SetupSocket(intfAddr, MulticastDNSPort, intf->index, &alias->multicastSocket4); 929 #if HAVE_IPV6 930 else if (alias->multicastSocket6 == -1 && intfAddr->sa_family == AF_INET6) 931 err = SetupSocket(intfAddr, MulticastDNSPort, intf->index, &alias->multicastSocket6); 932 #endif 933 } 934 935 // If interface is a direct link, address record will be marked as kDNSRecordTypeKnownUnique 936 // and skip the probe phase of the probe/announce packet sequence. 937 intf->coreIntf.DirectLink = mDNSfalse; 938 #ifdef DIRECTLINK_INTERFACE_NAME 939 if (strcmp(intfName, STRINGIFY(DIRECTLINK_INTERFACE_NAME)) == 0) 940 intf->coreIntf.DirectLink = mDNStrue; 941 #endif 942 intf->coreIntf.SupportsUnicastMDNSResponse = mDNStrue; 943 944 // The interface is all ready to go, let's register it with the mDNS core. 945 if (err == 0) 946 err = mDNS_RegisterInterface(m, &intf->coreIntf, NormalActivation); 947 948 // Clean up. 949 if (err == 0) 950 { 951 num_registered_interfaces++; 952 debugf("SetupOneInterface: %s %#a Registered", intf->intfName, &intf->coreIntf.ip); 953 if (gMDNSPlatformPosixVerboseLevel > 0) 954 fprintf(stderr, "Registered interface %s\n", intf->intfName); 955 } 956 else 957 { 958 // Use intfName instead of intf->intfName in the next line to avoid dereferencing NULL. 959 debugf("SetupOneInterface: %s %#a failed to register %d", intfName, &intf->coreIntf.ip, err); 960 if (intf) { FreePosixNetworkInterface(intf); intf = NULL; } 961 } 962 963 assert((err == 0) == (intf != NULL)); 964 965 return err; 966 } 967 968 // Call get_ifi_info() to obtain a list of active interfaces and call SetupOneInterface() on each one. 969 mDNSlocal int SetupInterfaceList(mDNS *const m) 970 { 971 mDNSBool foundav4 = mDNSfalse; 972 int err = 0; 973 struct ifi_info *intfList = get_ifi_info(AF_INET, mDNStrue); 974 struct ifi_info *firstLoopback = NULL; 975 976 assert(m != NULL); 977 debugf("SetupInterfaceList"); 978 979 if (intfList == NULL) err = ENOENT; 980 981 #if HAVE_IPV6 982 if (err == 0) /* Link the IPv6 list to the end of the IPv4 list */ 983 { 984 struct ifi_info **p = &intfList; 985 while (*p) p = &(*p)->ifi_next; 986 *p = get_ifi_info(AF_INET6, mDNStrue); 987 } 988 #endif 989 990 if (err == 0) 991 { 992 struct ifi_info *i = intfList; 993 while (i) 994 { 995 if ( ((i->ifi_addr->sa_family == AF_INET) 996 #if HAVE_IPV6 997 || (i->ifi_addr->sa_family == AF_INET6) 998 #endif 999 ) && (i->ifi_flags & IFF_UP) && !(i->ifi_flags & IFF_POINTOPOINT)) 1000 { 1001 if (i->ifi_flags & IFF_LOOPBACK) 1002 { 1003 if (firstLoopback == NULL) 1004 firstLoopback = i; 1005 } 1006 else 1007 { 1008 if (SetupOneInterface(m, i->ifi_addr, i->ifi_netmask, i->ifi_name, i->ifi_index) == 0) 1009 if (i->ifi_addr->sa_family == AF_INET) 1010 foundav4 = mDNStrue; 1011 } 1012 } 1013 i = i->ifi_next; 1014 } 1015 1016 // If we found no normal interfaces but we did find a loopback interface, register the 1017 // loopback interface. This allows self-discovery if no interfaces are configured. 1018 // Temporary workaround: Multicast loopback on IPv6 interfaces appears not to work. 1019 // In the interim, we skip loopback interface only if we found at least one v4 interface to use 1020 // if ((m->HostInterfaces == NULL) && (firstLoopback != NULL)) 1021 if (!foundav4 && firstLoopback) 1022 (void) SetupOneInterface(m, firstLoopback->ifi_addr, firstLoopback->ifi_netmask, firstLoopback->ifi_name, firstLoopback->ifi_index); 1023 } 1024 1025 // Clean up. 1026 if (intfList != NULL) free_ifi_info(intfList); 1027 1028 // Clean up any interfaces that have been hanging around on the RecentInterfaces list for more than a minute 1029 PosixNetworkInterface **ri = &gRecentInterfaces; 1030 const mDNSs32 utc = mDNSPlatformUTC(); 1031 while (*ri) 1032 { 1033 PosixNetworkInterface *pi = *ri; 1034 if (utc - pi->LastSeen < 60) ri = (PosixNetworkInterface **)&pi->coreIntf.next; 1035 else { *ri = (PosixNetworkInterface *)pi->coreIntf.next; free(pi); } 1036 } 1037 1038 return err; 1039 } 1040 1041 #if USES_NETLINK 1042 1043 // See <http://www.faqs.org/rfcs/rfc3549.html> for a description of NetLink 1044 1045 // Open a socket that will receive interface change notifications 1046 mDNSlocal mStatus OpenIfNotifySocket(int *pFD) 1047 { 1048 mStatus err = mStatus_NoError; 1049 struct sockaddr_nl snl; 1050 int sock; 1051 int ret; 1052 1053 sock = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE); 1054 if (sock < 0) 1055 return errno; 1056 1057 // Configure read to be non-blocking because inbound msg size is not known in advance 1058 (void) fcntl(sock, F_SETFL, O_NONBLOCK); 1059 1060 /* Subscribe the socket to Link & IP addr notifications. */ 1061 mDNSPlatformMemZero(&snl, sizeof snl); 1062 snl.nl_family = AF_NETLINK; 1063 snl.nl_groups = RTMGRP_LINK | RTMGRP_IPV4_IFADDR; 1064 ret = bind(sock, (struct sockaddr *) &snl, sizeof snl); 1065 if (0 == ret) 1066 *pFD = sock; 1067 else 1068 err = errno; 1069 1070 return err; 1071 } 1072 1073 #if MDNS_DEBUGMSGS 1074 mDNSlocal void PrintNetLinkMsg(const struct nlmsghdr *pNLMsg) 1075 { 1076 const char *kNLMsgTypes[] = { "", "NLMSG_NOOP", "NLMSG_ERROR", "NLMSG_DONE", "NLMSG_OVERRUN" }; 1077 const char *kNLRtMsgTypes[] = { "RTM_NEWLINK", "RTM_DELLINK", "RTM_GETLINK", "RTM_NEWADDR", "RTM_DELADDR", "RTM_GETADDR" }; 1078 1079 printf("nlmsghdr len=%d, type=%s, flags=0x%x\n", pNLMsg->nlmsg_len, 1080 pNLMsg->nlmsg_type < RTM_BASE ? kNLMsgTypes[pNLMsg->nlmsg_type] : kNLRtMsgTypes[pNLMsg->nlmsg_type - RTM_BASE], 1081 pNLMsg->nlmsg_flags); 1082 1083 if (RTM_NEWLINK <= pNLMsg->nlmsg_type && pNLMsg->nlmsg_type <= RTM_GETLINK) 1084 { 1085 struct ifinfomsg *pIfInfo = (struct ifinfomsg*) NLMSG_DATA(pNLMsg); 1086 printf("ifinfomsg family=%d, type=%d, index=%d, flags=0x%x, change=0x%x\n", pIfInfo->ifi_family, 1087 pIfInfo->ifi_type, pIfInfo->ifi_index, pIfInfo->ifi_flags, pIfInfo->ifi_change); 1088 1089 } 1090 else if (RTM_NEWADDR <= pNLMsg->nlmsg_type && pNLMsg->nlmsg_type <= RTM_GETADDR) 1091 { 1092 struct ifaddrmsg *pIfAddr = (struct ifaddrmsg*) NLMSG_DATA(pNLMsg); 1093 printf("ifaddrmsg family=%d, index=%d, flags=0x%x\n", pIfAddr->ifa_family, 1094 pIfAddr->ifa_index, pIfAddr->ifa_flags); 1095 } 1096 printf("\n"); 1097 } 1098 #endif 1099 1100 mDNSlocal mDNSu32 ProcessRoutingNotification(int sd) 1101 // Read through the messages on sd and if any indicate that any interface records should 1102 // be torn down and rebuilt, return affected indices as a bitmask. Otherwise return 0. 1103 { 1104 ssize_t readCount; 1105 char buff[4096]; 1106 struct nlmsghdr *pNLMsg = (struct nlmsghdr*) buff; 1107 mDNSu32 result = 0; 1108 1109 // The structure here is more complex than it really ought to be because, 1110 // unfortunately, there's no good way to size a buffer in advance large 1111 // enough to hold all pending data and so avoid message fragmentation. 1112 // (Note that FIONREAD is not supported on AF_NETLINK.) 1113 1114 readCount = read(sd, buff, sizeof buff); 1115 while (1) 1116 { 1117 // Make sure we've got an entire nlmsghdr in the buffer, and payload, too. 1118 // If not, discard already-processed messages in buffer and read more data. 1119 if (((char*) &pNLMsg[1] > (buff + readCount)) || // i.e. *pNLMsg extends off end of buffer 1120 ((char*) pNLMsg + pNLMsg->nlmsg_len > (buff + readCount))) 1121 { 1122 if (buff < (char*) pNLMsg) // we have space to shuffle 1123 { 1124 // discard processed data 1125 readCount -= ((char*) pNLMsg - buff); 1126 memmove(buff, pNLMsg, readCount); 1127 pNLMsg = (struct nlmsghdr*) buff; 1128 1129 // read more data 1130 readCount += read(sd, buff + readCount, sizeof buff - readCount); 1131 continue; // spin around and revalidate with new readCount 1132 } 1133 else 1134 break; // Otherwise message does not fit in buffer 1135 } 1136 1137 #if MDNS_DEBUGMSGS 1138 PrintNetLinkMsg(pNLMsg); 1139 #endif 1140 1141 // Process the NetLink message 1142 if (pNLMsg->nlmsg_type == RTM_GETLINK || pNLMsg->nlmsg_type == RTM_NEWLINK) 1143 result |= 1 << ((struct ifinfomsg*) NLMSG_DATA(pNLMsg))->ifi_index; 1144 else if (pNLMsg->nlmsg_type == RTM_DELADDR || pNLMsg->nlmsg_type == RTM_NEWADDR) 1145 result |= 1 << ((struct ifaddrmsg*) NLMSG_DATA(pNLMsg))->ifa_index; 1146 1147 // Advance pNLMsg to the next message in the buffer 1148 if ((pNLMsg->nlmsg_flags & NLM_F_MULTI) != 0 && pNLMsg->nlmsg_type != NLMSG_DONE) 1149 { 1150 ssize_t len = readCount - ((char*)pNLMsg - buff); 1151 pNLMsg = NLMSG_NEXT(pNLMsg, len); 1152 } 1153 else 1154 break; // all done! 1155 } 1156 1157 return result; 1158 } 1159 1160 #else // USES_NETLINK 1161 1162 // Open a socket that will receive interface change notifications 1163 mDNSlocal mStatus OpenIfNotifySocket(int *pFD) 1164 { 1165 *pFD = socket(AF_ROUTE, SOCK_RAW, 0); 1166 1167 if (*pFD < 0) 1168 return mStatus_UnknownErr; 1169 1170 // Configure read to be non-blocking because inbound msg size is not known in advance 1171 (void) fcntl(*pFD, F_SETFL, O_NONBLOCK); 1172 1173 return mStatus_NoError; 1174 } 1175 1176 #if MDNS_DEBUGMSGS 1177 mDNSlocal void PrintRoutingSocketMsg(const struct ifa_msghdr *pRSMsg) 1178 { 1179 const char *kRSMsgTypes[] = { "", "RTM_ADD", "RTM_DELETE", "RTM_CHANGE", "RTM_GET", "RTM_LOSING", 1180 "RTM_REDIRECT", "RTM_MISS", "RTM_LOCK", "RTM_OLDADD", "RTM_OLDDEL", "RTM_RESOLVE", 1181 "RTM_NEWADDR", "RTM_DELADDR", "RTM_IFINFO", "RTM_NEWMADDR", "RTM_DELMADDR" }; 1182 1183 int index = pRSMsg->ifam_type == RTM_IFINFO ? ((struct if_msghdr*) pRSMsg)->ifm_index : pRSMsg->ifam_index; 1184 1185 printf("ifa_msghdr len=%d, type=%s, index=%d\n", pRSMsg->ifam_msglen, kRSMsgTypes[pRSMsg->ifam_type], index); 1186 } 1187 #endif 1188 1189 mDNSlocal mDNSu32 ProcessRoutingNotification(int sd) 1190 // Read through the messages on sd and if any indicate that any interface records should 1191 // be torn down and rebuilt, return affected indices as a bitmask. Otherwise return 0. 1192 { 1193 ssize_t readCount; 1194 char buff[4096]; 1195 struct ifa_msghdr *pRSMsg = (struct ifa_msghdr*) buff; 1196 mDNSu32 result = 0; 1197 1198 readCount = read(sd, buff, sizeof buff); 1199 if (readCount < (ssize_t) sizeof(struct ifa_msghdr)) 1200 return mStatus_UnsupportedErr; // cannot decipher message 1201 1202 #if MDNS_DEBUGMSGS 1203 PrintRoutingSocketMsg(pRSMsg); 1204 #endif 1205 1206 // Process the message 1207 switch (pRSMsg->ifam_type) 1208 { 1209 case RTM_NEWADDR: 1210 case RTM_DELADDR: 1211 case RTM_IFINFO: 1212 /* 1213 * ADD & DELETE are happening when IPv6 announces are changing, 1214 * and for some reason it will stop mdnsd to announce IPv6 1215 * addresses. So we force mdnsd to check interfaces. 1216 */ 1217 case RTM_ADD: 1218 case RTM_DELETE: 1219 if (pRSMsg->ifam_type == RTM_IFINFO) 1220 result |= 1 << ((struct if_msghdr*) pRSMsg)->ifm_index; 1221 else 1222 result |= 1 << pRSMsg->ifam_index; 1223 break; 1224 } 1225 1226 return result; 1227 } 1228 1229 #endif // USES_NETLINK 1230 1231 // Called when data appears on interface change notification socket 1232 mDNSlocal void InterfaceChangeCallback(int fd, short filter, void *context) 1233 { 1234 IfChangeRec *pChgRec = (IfChangeRec*) context; 1235 fd_set readFDs; 1236 mDNSu32 changedInterfaces = 0; 1237 struct timeval zeroTimeout = { 0, 0 }; 1238 1239 (void)fd; // Unused 1240 (void)filter; // Unused 1241 1242 FD_ZERO(&readFDs); 1243 FD_SET(pChgRec->NotifySD, &readFDs); 1244 1245 do 1246 { 1247 changedInterfaces |= ProcessRoutingNotification(pChgRec->NotifySD); 1248 } 1249 while (0 < select(pChgRec->NotifySD + 1, &readFDs, (fd_set*) NULL, (fd_set*) NULL, &zeroTimeout)); 1250 1251 // Currently we rebuild the entire interface list whenever any interface change is 1252 // detected. If this ever proves to be a performance issue in a multi-homed 1253 // configuration, more care should be paid to changedInterfaces. 1254 if (changedInterfaces) 1255 mDNSPlatformPosixRefreshInterfaceList(pChgRec->mDNS); 1256 } 1257 1258 // Register with either a Routing Socket or RtNetLink to listen for interface changes. 1259 mDNSlocal mStatus WatchForInterfaceChange(mDNS *const m) 1260 { 1261 mStatus err; 1262 IfChangeRec *pChgRec; 1263 1264 pChgRec = (IfChangeRec*) mDNSPlatformMemAllocate(sizeof *pChgRec); 1265 if (pChgRec == NULL) 1266 return mStatus_NoMemoryErr; 1267 1268 pChgRec->mDNS = m; 1269 err = OpenIfNotifySocket(&pChgRec->NotifySD); 1270 if (err == 0) 1271 err = mDNSPosixAddFDToEventLoop(pChgRec->NotifySD, InterfaceChangeCallback, pChgRec); 1272 1273 return err; 1274 } 1275 1276 // Test to see if we're the first client running on UDP port 5353, by trying to bind to 5353 without using SO_REUSEPORT. 1277 // If we fail, someone else got here first. That's not a big problem; we can share the port for multicast responses -- 1278 // we just need to be aware that we shouldn't expect to successfully receive unicast UDP responses. 1279 mDNSlocal mDNSBool mDNSPlatformInit_CanReceiveUnicast(void) 1280 { 1281 int err; 1282 int s = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP); 1283 struct sockaddr_in s5353; 1284 s5353.sin_family = AF_INET; 1285 s5353.sin_port = MulticastDNSPort.NotAnInteger; 1286 s5353.sin_addr.s_addr = 0; 1287 err = bind(s, (struct sockaddr *)&s5353, sizeof(s5353)); 1288 close(s); 1289 if (err) debugf("No unicast UDP responses"); 1290 else debugf("Unicast UDP responses okay"); 1291 return(err == 0); 1292 } 1293 1294 // mDNS core calls this routine to initialise the platform-specific data. 1295 mDNSexport mStatus mDNSPlatformInit(mDNS *const m) 1296 { 1297 int err = 0; 1298 struct sockaddr sa; 1299 assert(m != NULL); 1300 1301 if (mDNSPlatformInit_CanReceiveUnicast()) m->CanReceiveUnicastOn5353 = mDNStrue; 1302 1303 // Tell mDNS core the names of this machine. 1304 1305 // Set up the nice label 1306 m->nicelabel.c[0] = 0; 1307 GetUserSpecifiedFriendlyComputerName(&m->nicelabel); 1308 if (m->nicelabel.c[0] == 0) MakeDomainLabelFromLiteralString(&m->nicelabel, "Computer"); 1309 1310 // Set up the RFC 1034-compliant label 1311 m->hostlabel.c[0] = 0; 1312 GetUserSpecifiedRFC1034ComputerName(&m->hostlabel); 1313 if (m->hostlabel.c[0] == 0) MakeDomainLabelFromLiteralString(&m->hostlabel, "Computer"); 1314 1315 mDNS_SetFQDN(m); 1316 1317 sa.sa_family = AF_INET; 1318 m->p->unicastSocket4 = -1; 1319 if (err == mStatus_NoError) err = SetupSocket(&sa, zeroIPPort, 0, &m->p->unicastSocket4); 1320 #if HAVE_IPV6 1321 sa.sa_family = AF_INET6; 1322 m->p->unicastSocket6 = -1; 1323 if (err == mStatus_NoError) err = SetupSocket(&sa, zeroIPPort, 0, &m->p->unicastSocket6); 1324 #endif 1325 1326 // Tell mDNS core about the network interfaces on this machine. 1327 if (err == mStatus_NoError) err = SetupInterfaceList(m); 1328 1329 // Tell mDNS core about DNS Servers 1330 mDNS_Lock(m); 1331 if (err == mStatus_NoError) ParseDNSServers(m, uDNS_SERVERS_FILE); 1332 mDNS_Unlock(m); 1333 1334 if (err == mStatus_NoError) 1335 { 1336 err = WatchForInterfaceChange(m); 1337 // Failure to observe interface changes is non-fatal. 1338 if (err != mStatus_NoError) 1339 { 1340 fprintf(stderr, "mDNS(%d) WARNING: Unable to detect interface changes (%d).\n", 1341 (int)getpid(), err); 1342 err = mStatus_NoError; 1343 } 1344 } 1345 1346 // We don't do asynchronous initialization on the Posix platform, so by the time 1347 // we get here the setup will already have succeeded or failed. If it succeeded, 1348 // we should just call mDNSCoreInitComplete() immediately. 1349 if (err == mStatus_NoError) 1350 mDNSCoreInitComplete(m, mStatus_NoError); 1351 1352 return PosixErrorToStatus(err); 1353 } 1354 1355 // mDNS core calls this routine to clean up the platform-specific data. 1356 // In our case all we need to do is to tear down every network interface. 1357 mDNSexport void mDNSPlatformClose(mDNS *const m) 1358 { 1359 int rv; 1360 assert(m != NULL); 1361 ClearInterfaceList(m); 1362 if (m->p->unicastSocket4 != -1) 1363 { 1364 rv = close(m->p->unicastSocket4); 1365 assert(rv == 0); 1366 } 1367 #if HAVE_IPV6 1368 if (m->p->unicastSocket6 != -1) 1369 { 1370 rv = close(m->p->unicastSocket6); 1371 assert(rv == 0); 1372 } 1373 #endif 1374 } 1375 1376 // This is used internally by InterfaceChangeCallback. 1377 // It's also exported so that the Standalone Responder (mDNSResponderPosix) 1378 // can call it in response to a SIGHUP (mainly for debugging purposes). 1379 mDNSexport mStatus mDNSPlatformPosixRefreshInterfaceList(mDNS *const m) 1380 { 1381 int err; 1382 // This is a pretty heavyweight way to process interface changes -- 1383 // destroying the entire interface list and then making fresh one from scratch. 1384 // We should make it like the OS X version, which leaves unchanged interfaces alone. 1385 ClearInterfaceList(m); 1386 err = SetupInterfaceList(m); 1387 return PosixErrorToStatus(err); 1388 } 1389 1390 #if COMPILER_LIKES_PRAGMA_MARK 1391 #pragma mark ***** Locking 1392 #endif 1393 1394 // On the Posix platform, locking is a no-op because we only ever enter 1395 // mDNS core on the main thread. 1396 1397 // mDNS core calls this routine when it wants to prevent 1398 // the platform from reentering mDNS core code. 1399 mDNSexport void mDNSPlatformLock (const mDNS *const m) 1400 { 1401 (void) m; // Unused 1402 } 1403 1404 // mDNS core calls this routine when it release the lock taken by 1405 // mDNSPlatformLock and allow the platform to reenter mDNS core code. 1406 mDNSexport void mDNSPlatformUnlock (const mDNS *const m) 1407 { 1408 (void) m; // Unused 1409 } 1410 1411 #if COMPILER_LIKES_PRAGMA_MARK 1412 #pragma mark ***** Strings 1413 #endif 1414 1415 // mDNS core calls this routine to copy C strings. 1416 // On the Posix platform this maps directly to the ANSI C strcpy. 1417 mDNSexport void mDNSPlatformStrCopy(void *dst, const void *src) 1418 { 1419 strcpy((char *)dst, (const char *)src); 1420 } 1421 1422 mDNSexport mDNSu32 mDNSPlatformStrLCopy(void *dst, const void *src, mDNSu32 len) 1423 { 1424 #if HAVE_STRLCPY 1425 return ((mDNSu32)strlcpy((char *)dst, (const char *)src, len)); 1426 #else 1427 size_t srcLen; 1428 1429 srcLen = strlen((const char *)src); 1430 if (srcLen < len) 1431 { 1432 memcpy(dst, src, srcLen + 1); 1433 } 1434 else if (len > 0) 1435 { 1436 memcpy(dst, src, len - 1); 1437 ((char *)dst)[len - 1] = '\0'; 1438 } 1439 1440 return ((mDNSu32)srcLen); 1441 #endif 1442 } 1443 1444 // mDNS core calls this routine to get the length of a C string. 1445 // On the Posix platform this maps directly to the ANSI C strlen. 1446 mDNSexport mDNSu32 mDNSPlatformStrLen (const void *src) 1447 { 1448 return strlen((const char*)src); 1449 } 1450 1451 // mDNS core calls this routine to copy memory. 1452 // On the Posix platform this maps directly to the ANSI C memcpy. 1453 mDNSexport void mDNSPlatformMemCopy(void *dst, const void *src, mDNSu32 len) 1454 { 1455 memcpy(dst, src, len); 1456 } 1457 1458 // mDNS core calls this routine to test whether blocks of memory are byte-for-byte 1459 // identical. On the Posix platform this is a simple wrapper around ANSI C memcmp. 1460 mDNSexport mDNSBool mDNSPlatformMemSame(const void *dst, const void *src, mDNSu32 len) 1461 { 1462 return memcmp(dst, src, len) == 0; 1463 } 1464 1465 // If the caller wants to know the exact return of memcmp, then use this instead 1466 // of mDNSPlatformMemSame 1467 mDNSexport int mDNSPlatformMemCmp(const void *dst, const void *src, mDNSu32 len) 1468 { 1469 return (memcmp(dst, src, len)); 1470 } 1471 1472 mDNSexport void mDNSPlatformQsort(void *base, int nel, int width, int (*compar)(const void *, const void *)) 1473 { 1474 (void)qsort(base, nel, width, compar); 1475 } 1476 1477 // DNSSEC stub functions 1478 mDNSexport void VerifySignature(mDNS *const m, DNSSECVerifier *dv, DNSQuestion *q) 1479 { 1480 (void)m; 1481 (void)dv; 1482 (void)q; 1483 } 1484 1485 mDNSexport mDNSBool AddNSECSForCacheRecord(mDNS *const m, CacheRecord *crlist, CacheRecord *negcr, mDNSu8 rcode) 1486 { 1487 (void)m; 1488 (void)crlist; 1489 (void)negcr; 1490 (void)rcode; 1491 return mDNSfalse; 1492 } 1493 1494 mDNSexport void BumpDNSSECStats(mDNS *const m, DNSSECStatsAction action, DNSSECStatsType type, mDNSu32 value) 1495 { 1496 (void)m; 1497 (void)action; 1498 (void)type; 1499 (void)value; 1500 } 1501 1502 // Proxy stub functions 1503 mDNSexport mDNSu8 *DNSProxySetAttributes(DNSQuestion *q, DNSMessageHeader *h, DNSMessage *msg, mDNSu8 *ptr, mDNSu8 *limit) 1504 { 1505 (void) q; 1506 (void) h; 1507 (void) msg; 1508 (void) ptr; 1509 (void) limit; 1510 1511 return ptr; 1512 } 1513 1514 mDNSexport void DNSProxyInit(mDNSu32 IpIfArr[], mDNSu32 OpIf) 1515 { 1516 (void) IpIfArr; 1517 (void) OpIf; 1518 } 1519 1520 mDNSexport void DNSProxyTerminate(void) 1521 { 1522 } 1523 1524 // mDNS core calls this routine to clear blocks of memory. 1525 // On the Posix platform this is a simple wrapper around ANSI C memset. 1526 mDNSexport void mDNSPlatformMemZero(void *dst, mDNSu32 len) 1527 { 1528 memset(dst, 0, len); 1529 } 1530 1531 mDNSexport void * mDNSPlatformMemAllocate(mDNSu32 len) { return(malloc(len)); } 1532 mDNSexport void mDNSPlatformMemFree (void *mem) { free(mem); } 1533 1534 #if _PLATFORM_HAS_STRONG_PRNG_ 1535 mDNSexport mDNSu32 mDNSPlatformRandomNumber(void) 1536 { 1537 return(arc4random()); 1538 } 1539 #else 1540 mDNSexport mDNSu32 mDNSPlatformRandomSeed(void) 1541 { 1542 struct timeval tv; 1543 gettimeofday(&tv, NULL); 1544 return(tv.tv_usec); 1545 } 1546 #endif 1547 1548 mDNSexport mDNSs32 mDNSPlatformOneSecond = 1024; 1549 1550 mDNSexport mStatus mDNSPlatformTimeInit(void) 1551 { 1552 // No special setup is required on Posix -- we just use gettimeofday(); 1553 // This is not really safe, because gettimeofday can go backwards if the user manually changes the date or time 1554 // We should find a better way to do this 1555 return(mStatus_NoError); 1556 } 1557 1558 mDNSexport mDNSs32 mDNSPlatformRawTime() 1559 { 1560 struct timeval tv; 1561 gettimeofday(&tv, NULL); 1562 // tv.tv_sec is seconds since 1st January 1970 (GMT, with no adjustment for daylight savings time) 1563 // tv.tv_usec is microseconds since the start of this second (i.e. values 0 to 999999) 1564 // We use the lower 22 bits of tv.tv_sec for the top 22 bits of our result 1565 // and we multiply tv.tv_usec by 16 / 15625 to get a value in the range 0-1023 to go in the bottom 10 bits. 1566 // This gives us a proper modular (cyclic) counter that has a resolution of roughly 1ms (actually 1/1024 second) 1567 // and correctly cycles every 2^22 seconds (4194304 seconds = approx 48 days). 1568 return((tv.tv_sec << 10) | (tv.tv_usec * 16 / 15625)); 1569 } 1570 1571 mDNSexport mDNSs32 mDNSPlatformUTC(void) 1572 { 1573 return time(NULL); 1574 } 1575 1576 mDNSexport void mDNSPlatformSendWakeupPacket(mDNSInterfaceID InterfaceID, char *EthAddr, char *IPAddr, int iteration) 1577 { 1578 (void) InterfaceID; 1579 (void) EthAddr; 1580 (void) IPAddr; 1581 (void) iteration; 1582 } 1583 1584 mDNSexport mDNSBool mDNSPlatformValidRecordForInterface(const AuthRecord *rr, mDNSInterfaceID InterfaceID) 1585 { 1586 (void) rr; 1587 (void) InterfaceID; 1588 1589 return 1; 1590 } 1591 1592 mDNSexport mDNSBool mDNSPlatformValidQuestionForInterface(DNSQuestion *q, const NetworkInterfaceInfo *intf) 1593 { 1594 (void) q; 1595 (void) intf; 1596 1597 return 1; 1598 } 1599 1600 // Used for debugging purposes. For now, just set the buffer to zero 1601 mDNSexport void mDNSPlatformFormatTime(unsigned long te, mDNSu8 *buf, int bufsize) 1602 { 1603 (void) te; 1604 if (bufsize) buf[0] = 0; 1605 } 1606 1607 mDNSexport void mDNSPlatformSendKeepalive(mDNSAddr *sadd, mDNSAddr *dadd, mDNSIPPort *lport, mDNSIPPort *rport, mDNSu32 seq, mDNSu32 ack, mDNSu16 win) 1608 { 1609 (void) sadd; // Unused 1610 (void) dadd; // Unused 1611 (void) lport; // Unused 1612 (void) rport; // Unused 1613 (void) seq; // Unused 1614 (void) ack; // Unused 1615 (void) win; // Unused 1616 } 1617 1618 mDNSexport mStatus mDNSPlatformRetrieveTCPInfo(mDNSAddr *laddr, mDNSIPPort *lport, mDNSAddr *raddr, mDNSIPPort *rport, mDNSTCPInfo *mti) 1619 { 1620 (void) laddr; // Unused 1621 (void) raddr; // Unused 1622 (void) lport; // Unused 1623 (void) rport; // Unused 1624 (void) mti; // Unused 1625 1626 return mStatus_NoError; 1627 } 1628 1629 mDNSexport mStatus mDNSPlatformGetRemoteMacAddr(mDNSAddr *raddr) 1630 { 1631 (void) raddr; // Unused 1632 1633 return mStatus_NoError; 1634 } 1635 1636 mDNSexport mStatus mDNSPlatformStoreSPSMACAddr(mDNSAddr *spsaddr, char *ifname) 1637 { 1638 (void) spsaddr; // Unused 1639 (void) ifname; // Unused 1640 1641 return mStatus_NoError; 1642 } 1643 1644 mDNSexport mStatus mDNSPlatformClearSPSData(void) 1645 { 1646 return mStatus_NoError; 1647 } 1648 1649 mDNSexport mStatus mDNSPlatformStoreOwnerOptRecord(char *ifname, DNSMessage *msg, int length) 1650 { 1651 (void) ifname; // Unused 1652 (void) msg; // Unused 1653 (void) length; // Unused 1654 return mStatus_UnsupportedErr; 1655 } 1656 1657 mDNSexport mDNSu16 mDNSPlatformGetUDPPort(UDPSocket *sock) 1658 { 1659 (void) sock; // unused 1660 1661 return (mDNSu16)-1; 1662 } 1663 1664 mDNSexport mDNSBool mDNSPlatformInterfaceIsD2D(mDNSInterfaceID InterfaceID) 1665 { 1666 (void) InterfaceID; // unused 1667 1668 return mDNSfalse; 1669 } 1670 1671 mDNSexport void mDNSPlatformSetSocktOpt(void *sock, mDNSTransport_Type transType, mDNSAddr_Type addrType, const DNSQuestion *q) 1672 { 1673 (void) sock; 1674 (void) transType; 1675 (void) addrType; 1676 (void) q; 1677 } 1678 1679 mDNSexport mDNSs32 mDNSPlatformGetPID() 1680 { 1681 return 0; 1682 } 1683 1684 mDNSlocal void mDNSPosixAddToFDSet(int *nfds, fd_set *readfds, int s) 1685 { 1686 if (*nfds < s + 1) *nfds = s + 1; 1687 FD_SET(s, readfds); 1688 } 1689 1690 mDNSexport void mDNSPosixGetFDSet(mDNS *m, int *nfds, fd_set *readfds, struct timeval *timeout) 1691 { 1692 mDNSs32 ticks; 1693 struct timeval interval; 1694 1695 // 1. Call mDNS_Execute() to let mDNSCore do what it needs to do 1696 mDNSs32 nextevent = mDNS_Execute(m); 1697 1698 // 2. Build our list of active file descriptors 1699 PosixNetworkInterface *info = (PosixNetworkInterface *)(m->HostInterfaces); 1700 if (m->p->unicastSocket4 != -1) mDNSPosixAddToFDSet(nfds, readfds, m->p->unicastSocket4); 1701 #if HAVE_IPV6 1702 if (m->p->unicastSocket6 != -1) mDNSPosixAddToFDSet(nfds, readfds, m->p->unicastSocket6); 1703 #endif 1704 while (info) 1705 { 1706 if (info->multicastSocket4 != -1) mDNSPosixAddToFDSet(nfds, readfds, info->multicastSocket4); 1707 #if HAVE_IPV6 1708 if (info->multicastSocket6 != -1) mDNSPosixAddToFDSet(nfds, readfds, info->multicastSocket6); 1709 #endif 1710 info = (PosixNetworkInterface *)(info->coreIntf.next); 1711 } 1712 1713 // 3. Calculate the time remaining to the next scheduled event (in struct timeval format) 1714 ticks = nextevent - mDNS_TimeNow(m); 1715 if (ticks < 1) ticks = 1; 1716 interval.tv_sec = ticks >> 10; // The high 22 bits are seconds 1717 interval.tv_usec = ((ticks & 0x3FF) * 15625) / 16; // The low 10 bits are 1024ths 1718 1719 // 4. If client's proposed timeout is more than what we want, then reduce it 1720 if (timeout->tv_sec > interval.tv_sec || 1721 (timeout->tv_sec == interval.tv_sec && timeout->tv_usec > interval.tv_usec)) 1722 *timeout = interval; 1723 } 1724 1725 mDNSexport void mDNSPosixProcessFDSet(mDNS *const m, fd_set *readfds) 1726 { 1727 PosixNetworkInterface *info; 1728 assert(m != NULL); 1729 assert(readfds != NULL); 1730 info = (PosixNetworkInterface *)(m->HostInterfaces); 1731 1732 if (m->p->unicastSocket4 != -1 && FD_ISSET(m->p->unicastSocket4, readfds)) 1733 { 1734 FD_CLR(m->p->unicastSocket4, readfds); 1735 SocketDataReady(m, NULL, m->p->unicastSocket4); 1736 } 1737 #if HAVE_IPV6 1738 if (m->p->unicastSocket6 != -1 && FD_ISSET(m->p->unicastSocket6, readfds)) 1739 { 1740 FD_CLR(m->p->unicastSocket6, readfds); 1741 SocketDataReady(m, NULL, m->p->unicastSocket6); 1742 } 1743 #endif 1744 1745 while (info) 1746 { 1747 if (info->multicastSocket4 != -1 && FD_ISSET(info->multicastSocket4, readfds)) 1748 { 1749 FD_CLR(info->multicastSocket4, readfds); 1750 SocketDataReady(m, info, info->multicastSocket4); 1751 } 1752 #if HAVE_IPV6 1753 if (info->multicastSocket6 != -1 && FD_ISSET(info->multicastSocket6, readfds)) 1754 { 1755 FD_CLR(info->multicastSocket6, readfds); 1756 SocketDataReady(m, info, info->multicastSocket6); 1757 } 1758 #endif 1759 info = (PosixNetworkInterface *)(info->coreIntf.next); 1760 } 1761 } 1762 1763 // update gMaxFD 1764 mDNSlocal void DetermineMaxEventFD(void) 1765 { 1766 PosixEventSource *iSource; 1767 1768 gMaxFD = 0; 1769 for (iSource=(PosixEventSource*)gEventSources.Head; iSource; iSource = iSource->Next) 1770 if (gMaxFD < iSource->fd) 1771 gMaxFD = iSource->fd; 1772 } 1773 1774 // Add a file descriptor to the set that mDNSPosixRunEventLoopOnce() listens to. 1775 mStatus mDNSPosixAddFDToEventLoop(int fd, mDNSPosixEventCallback callback, void *context) 1776 { 1777 PosixEventSource *newSource; 1778 1779 if (gEventSources.LinkOffset == 0) 1780 InitLinkedList(&gEventSources, offsetof(PosixEventSource, Next)); 1781 1782 if (fd >= (int) FD_SETSIZE || fd < 0) 1783 return mStatus_UnsupportedErr; 1784 if (callback == NULL) 1785 return mStatus_BadParamErr; 1786 1787 newSource = (PosixEventSource*) malloc(sizeof *newSource); 1788 if (NULL == newSource) 1789 return mStatus_NoMemoryErr; 1790 1791 newSource->Callback = callback; 1792 newSource->Context = context; 1793 newSource->fd = fd; 1794 1795 AddToTail(&gEventSources, newSource); 1796 FD_SET(fd, &gEventFDs); 1797 1798 DetermineMaxEventFD(); 1799 1800 return mStatus_NoError; 1801 } 1802 1803 // Remove a file descriptor from the set that mDNSPosixRunEventLoopOnce() listens to. 1804 mStatus mDNSPosixRemoveFDFromEventLoop(int fd) 1805 { 1806 PosixEventSource *iSource; 1807 1808 for (iSource=(PosixEventSource*)gEventSources.Head; iSource; iSource = iSource->Next) 1809 { 1810 if (fd == iSource->fd) 1811 { 1812 FD_CLR(fd, &gEventFDs); 1813 RemoveFromList(&gEventSources, iSource); 1814 free(iSource); 1815 DetermineMaxEventFD(); 1816 return mStatus_NoError; 1817 } 1818 } 1819 return mStatus_NoSuchNameErr; 1820 } 1821 1822 // Simply note the received signal in gEventSignals. 1823 mDNSlocal void NoteSignal(int signum) 1824 { 1825 sigaddset(&gEventSignals, signum); 1826 } 1827 1828 // Tell the event package to listen for signal and report it in mDNSPosixRunEventLoopOnce(). 1829 mStatus mDNSPosixListenForSignalInEventLoop(int signum) 1830 { 1831 struct sigaction action; 1832 mStatus err; 1833 1834 mDNSPlatformMemZero(&action, sizeof action); // more portable than member-wise assignment 1835 action.sa_handler = NoteSignal; 1836 err = sigaction(signum, &action, (struct sigaction*) NULL); 1837 1838 sigaddset(&gEventSignalSet, signum); 1839 1840 return err; 1841 } 1842 1843 // Tell the event package to stop listening for signal in mDNSPosixRunEventLoopOnce(). 1844 mStatus mDNSPosixIgnoreSignalInEventLoop(int signum) 1845 { 1846 struct sigaction action; 1847 mStatus err; 1848 1849 mDNSPlatformMemZero(&action, sizeof action); // more portable than member-wise assignment 1850 action.sa_handler = SIG_DFL; 1851 err = sigaction(signum, &action, (struct sigaction*) NULL); 1852 1853 sigdelset(&gEventSignalSet, signum); 1854 1855 return err; 1856 } 1857 1858 // Do a single pass through the attendent event sources and dispatch any found to their callbacks. 1859 // Return as soon as internal timeout expires, or a signal we're listening for is received. 1860 mStatus mDNSPosixRunEventLoopOnce(mDNS *m, const struct timeval *pTimeout, 1861 sigset_t *pSignalsReceived, mDNSBool *pDataDispatched) 1862 { 1863 fd_set listenFDs = gEventFDs; 1864 int fdMax = 0, numReady; 1865 struct timeval timeout = *pTimeout; 1866 1867 // Include the sockets that are listening to the wire in our select() set 1868 mDNSPosixGetFDSet(m, &fdMax, &listenFDs, &timeout); // timeout may get modified 1869 if (fdMax < gMaxFD) 1870 fdMax = gMaxFD; 1871 1872 numReady = select(fdMax + 1, &listenFDs, (fd_set*) NULL, (fd_set*) NULL, &timeout); 1873 1874 // If any data appeared, invoke its callback 1875 if (numReady > 0) 1876 { 1877 PosixEventSource *iSource; 1878 1879 (void) mDNSPosixProcessFDSet(m, &listenFDs); // call this first to process wire data for clients 1880 1881 for (iSource=(PosixEventSource*)gEventSources.Head; iSource; iSource = iSource->Next) 1882 { 1883 if (FD_ISSET(iSource->fd, &listenFDs)) 1884 { 1885 iSource->Callback(iSource->fd, 0, iSource->Context); 1886 break; // in case callback removed elements from gEventSources 1887 } 1888 } 1889 *pDataDispatched = mDNStrue; 1890 } 1891 else 1892 *pDataDispatched = mDNSfalse; 1893 1894 (void) sigprocmask(SIG_BLOCK, &gEventSignalSet, (sigset_t*) NULL); 1895 *pSignalsReceived = gEventSignals; 1896 sigemptyset(&gEventSignals); 1897 (void) sigprocmask(SIG_UNBLOCK, &gEventSignalSet, (sigset_t*) NULL); 1898 1899 return mStatus_NoError; 1900 } 1901